<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>
<script>
    var str = "user=a123123&pwd=113123&email=123123@qq.com&phone=17386141517";
    //   => {user,pwd,phone,email}

    var data = {};
    var list = str.split("&");
    console.log(list);

    for (var i = 0; i < list.length; i++) {
        var item = list[i]; // 'user=a123123', 'pwd=113123'
        var key = item.split("=")[0];
        var val = item.split("=")[1];
        data[key] = val;
    }

    console.log(data);  // {{user,pwd,phone,email}}





</script>

</html>